Paralytic toxin profile of the marine dinoflagellateGymnodinium catenatumGraham from the Mexican Pacific as revealed by LC-MS/MS

Abstract

The paralytic shellfish toxin (PST) profiles of Gymnodinium catenatum Graham have been reported for several strains from the Pacific coast of Mexico cultured under different laboratory conditions, as well as from natural populations. Up to 15 saxitoxin analogues occurred and the quantity of each toxin depended on the growth phase and culture conditions. Previous analysis of toxin profiles of G. catenatum isolated from Mexico have been based on post-column oxidation liquid chromatography with fluorescence detection (LC-FLD), a method prone to artefacts and non-specificity, leading to misinterpretation of toxin composition. We describe, for the first time, the complete toxin profile for several G. catenatum strains from diverse locations of the Pacific coast of Mexico. The new results confirmed previous reports on the dominance of the less potent sulfocarbamoyl toxins (C1/2); significant differences, however, in the composition (e.g., absence of saxitoxin, gonyautoxin 2/3 and neosaxitoxin) were revealed in our confirmatory analysis. The LC-MS/MS analyses also indicated at least seven putative benzoyl toxin analogues and provided support for their existence. This new toxin profile shows a high similarity (> 80%) to the profiles reported from several regions around the world, suggesting low genetic variability among global populations.

Gymnodinium catenatum Graham isolated from the Portuguese coast: Toxin content and genetic characterization

“…Wild G. catenatum populations at the global scale as well as laboratory maintained cultures exhibit variation in PST profiles, but with consistent regional patterns (Oshima et al, 1993). For instance, most Australian strains produce a high proportion of C3 and C4 (Negri et al, , 2007 while strains from the Gulf of California are characterized by a high proportion of C1 and C2 and the absence of STX, GTX 2.3 and Neo (Bustillos-Guzmá n et al, 2015). Japanese isolates produce C1 and C2 derivatives but not C3 and C4 (Hallegraeff et al, 2012).…”

Paralytic Toxin Producing Dinoflagellates in Latin America: Ecology and Physiology

“…In these analysis, C1/2 analogs were the most abundant, with >85% on molar basis. Decarbamoyl toxins, such as dcSTX and dcNEO represented a mean average content <5% and no differences were found between the two culture media (Bustillos- Guzmán et al, 2015). The richness of GC analogs in Mexican isolates was confirmed but due to the lack of standards, they could not be quantified, but in terms of relative abundance (peak area cell −1 ) an interesting geographical increasing trend from strains from northern to southern regions was found (Bustillos- Guzmán et al, 2015).…”

“…The second was found in samples from Mexico: Bahía Concepción (BACO) and BAPAZ (Gárate-Lizárraga et al, 2004, 2006 in the GOLCA. However, the liquid chromatography with fluorescence detection (LC-FLD) method commonly used for these analyses has some withdrawals, and miss-identification may occur depending on the extraction methods, if two or more toxins have the same retention time or if phantom peaks are present they can compromise the identification of analogs (Bustillos- Guzmán et al, 2015). These patterns have to be further confirmed and analyzed by confirmatory methods such as LC coupled to mass spectrometry detectors alone or in tandem (LC-MS or LC-MS/MS).…”

Enzymes that detoxify marine toxins

“…Different types of inflammasome can form depending on the sensor components involved. Certain inflammasomes respond to a highly specific trigger: for example, those in mammalian cells containing the sensor pro tein NLRC4 respond to the presence of the bacterial protein flagellin 3,4 .…”

“…PSTs are produced by marine micro organisms, including cyanobacteria and dino flagellates 3,4 . They are responsible for the numbness, tingling and moresevere symp toms of paralytic shellfish poisoning (caused by eating shellfish contaminated with these toxins), and interfere with the voltagegated sodium channels that are responsible for trans mitting signals in the nervous system.…”